A large number of methods for producing fuel air mixtures for reciprocating internal combustion engines are known, and many are patented. As far as Applicant is aware, previously disclosed methods all attempt to produce a fuel vapor mixed thoroughly with air. In some of these methods, fuel is heated, some instances to approximately a boiling point of the fuel, in order to convert the fuel to a gas prior to its induction into a combustion chamber. Virtually all attempt to eliminate fuel droplets based on the belief that fuel droplets in the fuel/air mixture cause inefficient combustion and generate more pollutants in the exhaust.
However, providing a stoichiometric fuel/air mixture wherein the fuel is in a vapor form also provides a readily explosive mixture. This becomes a problem when loading on an engine causes pressure increases in combustion chambers thereof sufficient to raise a temperature of the fuel/air mixture to or beyond its ignition point. This in turn causes the fuel/air-mixture to explode all at once rather than burning evenly in an outward direction from the spark plug), a condition commonly known as “knock” or “ping” due to the noise created as bearings of the rotating parts of the engine are slammed together under the force of the explosion, which occurs as the piston is still moving upward in the cylinder. As might be imagined, such a condition is deleterious to bearings and other parts of the engine, and greatly shortens engine life.
In accordance with the present invention (referred to in one embodiment hereinafter as “Star Tube”), an apparatus for processing liquid fuel is provided, the process converting fuel into a fog-like aerosol having droplets of a predetermined maximum size with a minimum of vapor. The object of this invention is to promote faster burning of liquid fuel in internal combustion engines such as Otto-cycle engines, two-stroke engines, Wankel-type engines and other engines, including turbine engines, that compress a fuel/air mixture that is or close to being stoichiometrically correct just prior to ignition, thus reducing fuel octane requirements for engines of a given compression ratio and causing turbine engines to burn cleaner. This is achieved because fuel droplets “burn” at a slower rate than a gas/air mixture that explodes, thus reducing the tendency of an engine to knock. Here, it is believed that a fuel droplet within the aforementioned range may burn in layers, so that as an outer layer of the fuel droplet is burned off, oxygen is temporarily depleted around the droplet. Oxygen then surrounds the droplet as combustion gases around the droplet expand and dissipate, allowing the next layer to burn off. This process is repeated until the fuel droplet is fully burned.
It may also be possible that since, in the instant invention, fuel is initially sprayed into a confined tube, vapor saturation and cooling within the tube prevents further evaporation of the fuel droplets, causing the fuel droplets to remain at a relatively constant size as they travel to the combustion chamber. Here, as the fuel is sprayed into the tube, lighter, more volatile components of the fuel instantly flash into vapor and increase hydrocarbon vapor pressure within the tube, cooling and suppressing evaporation of the remaining fuel droplets. The heavier-component fuel droplets are processed by the Star Tube to reach a size sufficiently small so as to travel with a localized region of lighter-component fuel-saturated air into the combustion chamber.
In accordance with the foregoing, it is one object of the invention to provide apparatus for decreasing or eliminating engine knock by aerosolizing fuel into a fog of fuel droplets, the droplets being of a maximum predetermined size. It is another object of the invention to provide apparatus for generating a fuel/air mixture wherein the fuel is incorporated into the droplets to as great an extent as possible, with as little vapor as possible. It is yet another object of the invention to enable an internal combustion, spark ignition engine to operate normally without knock using a fuel of a lower octane rating than the engine would otherwise be required to use, and to increase efficiency of the engine. Other objects of the invention will become apparent upon a reading of the following appended specification.